1. Technical Field
This invention relates to internal combustion engines, and more particularly, to the combustion of an internal combustion engine.
2. Description of Related Art
In a typical combustion engine, fuel and air are mixed in a combustion chamber and the fuel and air mixture is combusted. The leftover hot gases produced by this combustion tend to occupy a far greater volume than the original fuel, thus creating an increase in pressure within the limited volume of the combustion chamber. The pressure can be used to do work, for example, to move a piston on a crankshaft or rotate the blades of a turbine. The energy can be converted to various types of motion or to produce thrust when directed out of a nozzle as in a rocket or jet engine.
For example, a reciprocating engine, also known as a piston engine, is a heat engine that uses one or more pistons to convert pressure into a rotating motion. There may be one or more pistons and each piston is enclosed inside a cylinder or combustion chamber. Gas is introduced into the combustion chamber, either already hot and under pressure such as in a steam engine, heated inside the cylinder either by ignition of a fuel air mixture such as in an internal combustion engine, or by contact with a hot heat exchanger in the cylinder. As the hot gases expand, pressure pushes the piston to the bottom of the cylinder or combustion chamber. The piston is returned to the cylinder top either by a flywheel or by the power from other pistons connected to the same shaft and the cycle starts again. Typically, the expanded or “exhausted” gases are removed from the cylinder by this stroke.